Swaging device and swaging method

ABSTRACT

A swaging device according to an aspect of the present invention swages an end of a tubular body and a circumferential edge of an end plate for closing an opening of the tubular body by utilizing a processing roller, in which the processing roller is connected to a robot, the robot being configured to control a position of the processing roller, and swaging is performed by sandwiching the end of the tubular body and the circumferential edge of the end plate by an inner roller and an outer roller, the inner roller being disposed inside the tubular body, the outer roller being disposed outside the tubular body so that the outer roller is opposed to the inner roller, and the outer roller being movable toward the inner roller.

INCORPORATION BY REFERENCE

This application is based upon and claims the benefit of priority fromJapanese patent application No. 2014-96760, filed on May 8, 2014, thedisclosure of which is incorporated herein in its entirety by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a swaging device and a swaging method.For example, the present invention relates to a swaging device and aswaging method in which an end of a tubular body fixed on a rotatabletable and a circumferential edge of an end plate for closing an openingof the tubular body are swaged together.

2. Description of Related Art

For example, a muffler of an automobile has usually a structure in whicha pressed article is attached to a main pipe by a swaging process. Insuch a swaging process, swaging is performed by pushing a roller into anend of a main pipe and a circumferential edge of a pressed article by aconforming method (or copying method) by using a model form (or die).

In a swaging device disclosed in Japanese Unexamined Patent ApplicationPublication No, 2001-300666, swaging is performed by placing a flange ofa tubular body formed by raising an end of the tubular body outward anda circumferential edge of an end plate for closing an opening of thetubular body on top of one another, holding the tubular body and the endplate by a core metal disposed inside the tubular body and receivingmeans disposed outside the end plate, pushing a roller onto the coremetal, sandwiching the flange of the tubular body and thecircumferential edge of the end plate by the roller and the core metal,and conforming the roller to a rotation of the tubular body.

The present inventors have found the following problem. A typicalswaging device has a configuration in which a model form is disposedinside a tubular body, and a roller is pushed so that the model form andthe roller sandwich the flange of the tubular body and thecircumferential edge of the end plate therebetween. In this process,since a reactive force to the force for pushing the flange of thetubular body and the circumferential edge of the end plate exerted bythe roller is transferred to the mechanism for controlling the positionof the roller, this mechanism needs to have a structure strong enough totolerate the reactive force, thus increasing the cost for the swagingdevice.

SUMMARY OF THE INVENTION

The present invention has been made in view of the above-describedcircumstances, and an object thereof is to provide a swaging device anda swaging method capable of simplifying the mechanism for controllingthe position of the roller(s) and contributing to a reduction in thecost thereof.

A first exemplary aspect of the present invention is a swaging devicethat swages an end of a tubular body and a circumferential edge of anend plate for closing an opening of the tubular body by utilizing aprocessing roller, in which

the processing roller is connected to a robot, the robot beingconfigured to control a position of the processing roller, and swagingis performed by sandwiching the end of the tubular body and thecircumferential edge of the end plate by an inner roller and an outerroller, the inner roller being disposed inside the tubular body, theouter roller being disposed outside the tubular body so that the outerroller is opposed to the inner roller, and the outer roller beingmovable toward the inner roller.

In the above-described swaging device, the force for pushing the end ofthe tubular body and the circumferential edge of the end plate exertedby the outer roller is roughly equal to the force acting to push backthe outer roller exerted by the inner roller, and their reactive forcesact on the robot so that they cancel out each other. As a result, thereactive force is not substantially transferred to the robot. Therefore,there is no need to construct the robot with a strong structure, thusmaking it possible to simplify the robot and to contribute to areduction in the cost thereof.

In the above-described swaging device, the robot preferably controlspositions of the inner and outer rollers so that rotation axes of theinner and outer rollers are in parallel with a surface sandwiched by theinner and outer rollers in the tubular body, and a direction in whichthe outer roller moves toward the inner roller is disposed on a normalof the sandwiched surface.

This makes it possible to reliably transfer a force acting for movingthe outer roller toward the inner roller to the end of the tubular bodyand the circumferential edge of the end plate.

The above-described swaging device preferably further includes a firstgrasping part and a second grasping part for sandwiching and fixing thetubular body, and

the first and second grasping parts can preferably be replaced accordingto a shape of the tubular body to be fixed.

As a result, the first and second grasping parts can be replacedaccording to the shape of the tubular body, thus increasing thegeneral-purpose property of the swaging device.

In the above-described swaging device, the outer roller preferablyincludes a first roller and a second roller, and

a straight line extending in a direction in which the first roller movestoward the inner roller and a straight line extending in a direction inwhich the second roller moves toward the inner roller preferablyintersect with each other.

As a result, the first and second rollers can be easily chosen, thusimproving the productivity.

In the above-described swaging device, the robot preferably controls thepositions of the inner and outer rollers so that their positions conformto the end of the tubular body and the circumferential edge of the endplate.

This makes it possible to omit the conforming mechanism (or copyingmechanism) of conventional swaging devices, thus simplifying the swagingdevice.

The above-described swaging device preferably further includes apressure adjustment unit that adjusts the force for pushing the end ofthe tubular body and the circumferential edge of the end plate in theouter roller to a value equal to or lower than a predeterminedthreshold.

This makes it possible to make the outer roller push the end of thetubular body and the circumferential edge of the end plate with anappropriate pressure.

The above-described swaging device preferably further includes arotatable table that rotates the tubular body, and

the robot and the rotatable table preferably operate in cooperation witheach other.

This makes it possible to narrow the operating range of the robot, thuscontributing to a reduction in the size of the robot.

Another exemplary aspect of the present invention is a swaging methodfor swaging an end of a tubular body and a circumferential edge of anend plate for closing an opening of the tubular body by utilizing aprocessing roller, the swaging method including:

controlling positions of an inner roller and an outer roller, the innerand outer rollers being the processing roller, the processing rollerbeing connected to a robot;

disposing the inner roller inside the tubular body;

disposing the outer roller outside the tubular body so that the outerroller is opposed to the inner roller; and

moving the outer roller toward the inner roller, sandwiching the end ofthe tubular body and the circumferential edge of the end plate by theouter and inner rollers, and thereby swaging the end of the tubular bodyand the circumferential edge of the end plate together.

In the above-described swaging method, a force for pushing the end ofthe tubular body and the circumferential edge of the end plate exertedby the outer roller is roughly equal to a force acting to push back theouter roller exerted by the inner roller, and their reactive forces acton the robot so that they cancel out each other. As a result, thereactive force is not substantially transferred to the robot. Therefore,there is no need to construct the robot with a strong structure, thusmaking it possible to simplify the robot and to contribute to areduction in the cost thereof.

In the above-described swaging method, the robot preferably controlspositions of the inner and outer rollers so that rotation axes of theinner and outer rollers are in parallel with a surface sandwiched by theinner and outer rollers in the tubular body, and a direction in whichthe outer roller moves toward the inner roller is perpendicular to thesandwiched surface.

This makes it possible to reliably transfer a force acting for movingthe outer roller toward the inner roller to the end of the tubular bodyand the circumferential edge of the end plate.

In the above-described swaging method, the robot preferably controls thepositions of the inner and outer rollers so that their positions conformto the end of the tubular body and the circumferential edge of the endplate.

This makes it possible to omit the conforming mechanism (or copyingmechanism) of conventional swaging devices, thus simplifying the swagingdevice.

According to the present invention, it is possible to provide a swagingdevice and a swaging method capable of simplifying the mechanism forcontrolling the position of the roller(s) and contributing to areduction in the cost thereof.

The above and other objects, features and advantages of the presentinvention will become more fully understood from the detaileddescription given hereinbelow and the accompanying drawings which aregiven by way of illustration only, and thus are not to be considered aslimiting the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front view showing a swaging device according to a firstexemplary embodiment;

FIG. 2 is an enlarged front view showing a swaging section of theswaging device according to the first exemplary embodiment;

FIG. 3 is a plan view showing a state where an end of a tubular body anda circumferential edge of an end plate are sandwiched by an inner rollerand an outer roller;

FIG. 4 is a block diagram of a control system of the swaging deviceaccording to the first exemplary embodiment;

FIG. 5 is a plan view showing a fixing jig provided in a rotatabletable;

FIG. 6 is a front view showing the fixing jig;

FIG. 7 shows a positional relation among the tubular body, and the innerand outer rollers when the tubular body is rotated;

FIG. 8 shows another tubular body that can be swaged by the swagingdevice according to the first exemplary embodiment;

FIG. 9 shows another tubular body that can be swaged by the swagingdevice according to the first exemplary embodiment;

FIG. 10 is a plan view showing a swaging section according to a secondexemplary embodiment;

FIG. 11 is a plan view showing the swaging section according to thesecond exemplary embodiment; and

FIGS. 12( a) to 12(e) schematically show a flow of a swaging processaccording to the second exemplary embodiment.

DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

Specific exemplary embodiments to which the present invention is appliedare explained hereinafter with reference to the drawings. However, thepresent invention is not limited to the below-shown exemplaryembodiments. Further, the following descriptions and the drawings may bepartly omitted and simplified as appropriate for clarifying theexplanations.

First Exemplary Embodiment

Firstly, an outline of a swaging device and a swaging method accordingto this exemplary embodiment is explained. FIG. 1 is a front viewshowing a swaging device according to this exemplary embodiment. FIG. 2is an enlarged front view showing a swaging section of the swagingdevice according to this exemplary embodiment. FIG. 3 is a plan viewshowing a state where an end of a tubular body and a circumferentialedge of an end plate are sandwiched by an inner roller and an outerroller.

A swaging device 1 according to this exemplary embodiment is used, forexample, to manufacture a muffler of an automobile. As shown in FIGS. 1and 2, the swaging device 1 swages an end of a tubular body 2 and acircumferential edge of an end plate 3 for closing an opening 2 a of thetubular body 2 by utilizing processing rollers 4.

Note that the processing rollers 4 are connected to a robot 5 thatcontrols the positions of the processing rollers 4. The processingrollers 4 includes an inner roller 6 disposed inside the tubular body 2and an outer roller 7 disposed outside the tubular body 2 so that theouter roller 7 is opposed to the inner roller 6. The outer roller 7 canbe moved toward the inner roller 6. The swaging device 1 sandwiches theend of the tubular body 2 and the circumferential edge of the end plate3 by the inner and outer rollers 6 and 7 and thereby swages themtogether.

That is, the swaging device and the swaging method according to thisexemplary embodiment control the robot 5, dispose the inner roller 6inside the tubular body 2, dispose the outer roller 7 outside thetubular body 2 so that the outer roller 7 is opposed to the inner roller6, sandwich the end of the tubular body 2 and the circumferential edgeof the end plate 3 by the inner and outer rollers 6 and 7 by moving theouter roller 7 toward the inner roller 6, and thereby swage themtogether.

In the above-described swaging device 1 and the swaging method, theforce for pushing the end of the tubular body 2 and the circumferentialedge of the end plate 3 exerted by the outer roller 7 is roughly equalto the force acting to push back the outer roller 7 exerted by the innerroller 6, and their reactive forces act on the robot 5 so that theycancel out each other. As a result, the reactive force is notsubstantially transferred to the robot 5. Therefore, there is no need toconstruct the robot 5 with a strong structure, thus making it possibleto simplify the robot 5 and to contribute to a reduction in the costthereof.

Next, a swaging device according to this exemplary embodiment isexplained in detail. FIG. 4 is a block diagram of a control system ofthe swaging device according to this exemplary embodiment. FIG. 5 is aplan view showing a fixing jig provided in a rotatable table. FIG. 6 isa front view showing the fixing jig.

A tubular body 2 and an end plate 3 used in this exemplary embodimentare explained hereinafter. Note that the following explanations of thetubular body 2 and the end plate 3 are given with reference to the rightside of FIG. 1.

The tubular body 2 is, for example, a main pipe of a rolled muffler ofan automobile, and is formed by shaping a steel plate into a tubularshape. As shown in the right side of FIG. 1, the tubular body 2according to this exemplary embodiment is a straight pipe having arounded-corner rectangular shape in a cross section when cut on a planeperpendicular to the height direction of the tubular body 2. Further, asshown in FIG. 2, each opened end of the tubular body 2 is formed as aflange 2 b that is formed by raising the end of the tubular body 2outward. However, the cross-sectional shape of the tubular body 2 as cuton the plane perpendicular to the height direction of the tubular body 2may be other shapes such as an ellipse and a circle. Further, the shapeof the tubular body 2 as viewed in the thickness direction may beroughly a trapezoid.

The end plate 3 is, for example, a pressed article formed by pressing asteel plate. The end plate 3 according to this exemplary embodiment hasa rounded-corner rectangular shape as viewed in the height direction ofthe end plate 3 so that it corresponds to the shape of the tubular body2. Further, an area inside a circumferential edge 3 a of the end plate 3is formed as a planar section 3 b that is recessed with reference to thecircumferential edge 3 a. Further, a rising section 3 c is interposedbetween the circumferential edge 3 a and the planar section 3 b. Notethat the shape of the end plate 3 may be defined as appropriateaccording to the shape of the opened end of the tubular body 2.

As shown in FIG. 2, when the planar section 3 b of the end plate 3 isinserted in the opening 2 a of the tubular body 2, the circumferentialedge 3 a of the end plate 3 is placed over the flange 2 b of the tubularbody 2 so that the surfaces of this edge and flange are roughly incontact with each other. Further, the surface of the rising part 3 c ofthe end plate 3 is roughly brought into contact with the innercircumferential surface of the tubular body 2. Note that variousparameters such as the angle at which the flange 2 b of the tubular body2 is raised outward, the size of the flange 2 b, the depth of the planarsection 3 b of the end plate 3, and the inclination angle of the risingpart 3 c may be defined as appropriate.

The swaging device 1 includes a rotatable table 8, a swaging section 9,a robot 5, and a control unit 10. As shown in FIG. 1, the rotatabletable 8 includes a fixing jig 11 and a main body 12.

As shown in FIGS. 5 and 6, the fixing jig 11 includes a first fixingpart 11 a, a second fixing part 11 b, a first drive mechanism 11 c, asecond drive mechanism 11 d, and a housing 11 e. Note that the followingexplanation of the fixing jig 11 is given with reference to the fixingjig 11 shown in FIGS. 5 and 6.

The first and second fixing parts 11 a and 11 b sandwich and fix thetubular body 2 therebetween. In this exemplary embodiment, the tubularbody 2 is inserted between the first and second fixing parts 11 a and 11b from above the fixing jig 11. Further, the first and second fixingparts 11 a and 11 b sandwich and fix the tubular body 2 in the thicknessdirection of the tubular body 2.

The first fixing part 11 a includes a grasping part 11 f and a framepart 11 g. The grasping part 11 f includes a recessed part 11 h thatcorresponds to one of the shapes obtained by dividing the tubular body 2into two sections in the thickness direction. The grasping part 11 f isremovably attached to the frame part 11 g by using, for example, anengaging structure. However, the only requirement is that the graspingpart 11 f should be removably attached to the frame part 11 g. That is,the grasping part 11 f may be attached to the frame part 11 g by fixingmeans other than the engaging structure, such as a bolt. The left andright ends of the frame part 11 g are connected to the first and seconddrive mechanisms 11 c and 11 d, respectively.

The second fixing part 11 b has a structure roughly identical to that ofthe first fixing part 11 a, and includes a grasping part 11 i and aframe part 11 j. The grasping part 11 i includes a recessed part 11 kthat corresponds to the other of the shapes obtained by dividing thetubular body 2 into two sections in the thickness direction. Therecessed part 11 k is opposed to the recessed part 11 h of the firstfixing part 11 a in the front/back direction of the fixing jig 11. Thatis, when the first fixing part 11 a is brought into contact with thesecond fixing part 11 b in the front/back direction of the fixing jig11, the shape formed by the recessed parts 11 h and 11 k of the firstand second fixing part 11 a and 11 b, respectively, corresponds to theexternal shape of the tubular body 2.

The grasping part 11 i is removably attached to the frame part 11 j byusing, for example, an engaging structure. However, the only requirementis that the grasping part 11 i should be removably attached to the framepart 11 j. That is, the grasping part 11 i may be attached to the framepart 11 j by fixing means other than the engaging structure, such as abolt. The left and right ends of the frame part 11 j are connected tothe first and second drive mechanisms 11 c and 11 d, respectively.

The first drive mechanism 11 c moves the left end of the fixing jig 11in each of the first and second fixing parts 11 a and 11 b in thefront/back direction of the fixing jig 11. The first drive mechanism 11c according to this exemplary embodiment is disposed so that therecessed parts 11 h and 11 k of the respective first and second fixingpart 11 a and 11 b are interposed between the first and second drivemechanisms 11 c and 11 d in the left/right direction of the fixing jig11. Further, the first drive mechanism 11 c includes rail members 11 land a rod screw 11 m.

The rail members 11 l are disposed roughly in parallel with the rodscrew 11 m and extend in the front/back direction of the fixing jig 11.Further, the rail members 11 l are arranged in the vertical direction(or, up/down direction) of the fixing jig 11 with intervalstherebetween, and each rail member 11 l is supported by the housing 11e. Further, the rail members 11 l are engaged with recesses formed inthe left end of the fixing jig 11 in each of the frame parts 11 g and 11j.

The rod screw 11 m is rotatably supported in the housing 11 e. Further,the rod screw 11 m is screwed into a threaded hole that is formed at theleft end of the fixing jig 11 and penetrates the fixing jig 11 in thefront/back direction of the fixing jig 11 in each of the frame parts 11g and 11 j.

The second drive mechanism 11 d moves the right end of the fixing jig 11in each of the first and second fixing parts 11 a and 11 b in thefront/back direction of the fixing jig 11. The second drive mechanism 11d according to this exemplary embodiment includes rail members 11 n anda rod screw 11 o.

The rail members 11 n are disposed roughly in parallel with the rodscrew 11 o and extend in the front/back direction of the fixing jig 11.Further, the rail members 11 n are arranged in the vertical direction ofthe fixing jig 11 with intervals therebetween, and both ends of eachrail member 11 n are supported by the housing 11 e. Further, the railmembers 11 n are engaged with recesses formed in the right end of thefixing jig 11 in each of the frame parts 11 g and 11 j.

The rod screw 11 o is rotatably supported in the housing 11 e. Further,the rod screw 11 o is screwed into a threaded hole that is formed at theright end of the fixing jig 11 and penetrates the fixing jig 11 in thefront/back direction of the fixing jig 11 in each of the frame parts 11g and 11 j.

The housing 11 e has a box shape with an opening formed on the top. Thehousing 11 e contains the first and second fixing parts 11 a and 11 b,and the first and second drive mechanisms 11 c and 11 d.

In the above-described fixing jig 11, when the rod screws 11 m and 11 oare rotated in one direction, the first and second fixing parts 11 a and11 b move so that they get closer to each other in the front/backdirection of the fixing jig 11. Further, when the rod screws 11 m and 11o are rotated in the other direction, the first and second fixing parts11 a and 11 b move away from each other in the front/back direction ofthe fixing jig 11.

Therefore, it is possible to sandwich and fix the tubular body 2 by therecessed parts 11 h and 11 k of the first and second fixing part 11 aand 11 b in the thickness direction of the tubular body 2, and unfix andrelease the tubular body 2.

In addition, each of the grasping parts 11 f and 11 i can be attachedand removed from the frame parts 11 g and 11 j, respectively, thusmaking it possible to replace the grasping parts 11 f and 11 i accordingto the shape of the tubular body 2 (i.e., the external shape of thetubular body 2) and thereby increase the general-purpose property of theswaging device 1.

Note that although the first and second fixing part 11 a and 11 b aremoved by rotating the rod screws 11 m and 11 o in this exemplaryembodiment, the first and second fixing part 11 a and 11 b may be movedby using an actuator(s) or the like in other embodiments. Further, theonly requirement is that it should be possible for at least one of thefirst and second fixing part 11 a and 11 b to be moved.

As shown in FIG. 1, the main body 12 includes a placement section 12 a,a support section 12 b, and a drive mechanism 12 c. Note that thefollowing explanation of the main body 12 is given with reference to themain body 12 shown in FIG. 1.

The placement section 12 a is disposed above the support section 12 b.The support section 12 b supports the placement section 12 a in such amanner that the placement section 12 a can rotate around an axis AX1extending in the vertical direction of the main body 12. Further, thedrive mechanism 12 c is disposed on the support section 12 b.

The drive mechanism 12 c includes a motor, a speed reducer, and so on,and its output shaft extends in the vertical direction of the main body12. This output shaft is connected to the lower surface of the placementsection 12 a. Further, the motor of the drive mechanism 12 c operatesbased on a control signal supplied from the control unit 10.

On the above-described placement section 12 a in the main body 12, thefixing jig 11 is placed and fixed so that an axis AX2 that passesthrough the center O1 (see FIG. 5) of the cross-sectional shape of thetubular body 2, which is fixed to the fixing jig 11, on a planeperpendicular to the height direction of the tubular body 2 and extendsin the vertical direction of the fixing jig 11 roughly coincides withthe rotation axis AX1 of the placement section 12 a.

As shown in FIG. 2, the swaging section 9 includes processing rollers 4,a guide mechanism 13, a drive mechanism 14, a connection section 15, anda pushing mechanism 16. Note that the following explanation of theswaging section 9 is given with reference to the swaging section 9 shownin FIG. 2.

As described above, the processing rollers 4 include an inner roller 6and an outer roller 7. The inner roller 6 has a cylindrical shape as afundamental shape, and includes a circumferential surface 6 a that comesinto contact with the rising part 3 c of the end plate 3. Further, theinner roller 6 is rotatably supported from above the inner roller 6 bythe connection section 15 through a rotation shaft 6 b in a cantileverfashion. This inner roller 6 can be removably attached to the rotationshaft 6 b by using fixing means such as a nut.

The outer roller 7 has a cylindrical shape as a fundamental shape, andincludes a circumferential surface 7 a for pushing the flange 2 b of thetubular body 2 and the circumferential edge 3 a of the end plate 3. Inroughly the center in the vertical direction of the swaging section 9 inthis circumferential surface 7 a, a recess 7 c for rolling in the flange2 b of the tubular body 2 and the circumferential edge 3 a of the endplate 3 and thereby swaging them together is formed.

Further, the outer roller 7 is rotatably supported from above the outerroller 7 by the guide mechanism 13 through a rotation shaft 7 b in acantilever fashion. This outer roller 7 can be removably attached to therotation shaft 7 b by using fixing means such as a nut. With theabove-described configuration, each of the inner and outer rollers 6 and7 can be replaced as desired.

The circumferential surface 7 a of the outer roller 7 is disposed so asto be opposed to the circumferential surface 6 a of the inner roller 6in the left/right direction of the swaging section 9. Further, therotation shaft 7 b of the outer roller 7 is disposed roughly in parallelwith the rotation shaft 6 b of the inner roller 6 as viewed in thefront/back direction of the swaging section 9, and extends in thevertical direction of the swaging section 9. Further, as shown in FIG.3, a straight line L1 that is perpendicular to the rotation shaft 6 b ofthe inner roller 6 and connects the rotation shaft 7 b of the outerroller 7 with the rotation shaft 6 b of the inner roller 6 extends inthe left/right direction of the swaging section 9.

The guide mechanism 13 guides the outer roller 7 in the left/rightdirection of the swaging section 9. The guide mechanism 13 according tothis exemplary embodiment includes a rail member(s) 13 a, a slider 13 b,and a support member 13 c. The rail member 13 a extends in theleft/right direction of the swaging section 9.

The slider 13 b is engaged with the rail member 13 a and fixed to theconnection section 15. The support member 13 c supports the rail member13 a, and the rotation shaft 7 b of the outer roller 7 is connected tothe left end of the support member 13 c.

The drive mechanism 14 includes a cylinder 14 a and apressurization/decompression unit 14 b. The cylinder 14 a is fixed tothe connection section 15 through a fixing jig 14 c. A rod 14 d of thecylinder 14 a is connected to the support member 13 c of the guidemechanism 13. Further, a central axis AX3 of the rod 14 d is located onthe straight line L1 as viewed in the vertical direction of the swagingsection 9 and extends in the left/right direction of the swaging section9.

The pressurization/decompression unit 14 b operates based on a controlsignal supplied from the control unit 10, and extends/contracts the rod14 d of the cylinder 14 a by pressurizing or decompressing the cylinder14 a by using a fluid or a gas.

The connection section 15 supports the inner roller 6, the guidemechanism 13 supporting the roller 7, and the drive mechanism 14.Further, the connection section 15 is connected to the robot 5. Thepushing mechanism 16 pushes the planar section 3 b of the end plate 3.The pushing mechanism 16 according to this exemplary embodiment includesa ball plunger and is fixed to the connection section 15.

When the above-described swaging section 9 extends the cylinder 14 a ofthe drive mechanism 14, the outer roller 7 is moved while being guidedby the guide mechanism 13 so that the outer roller 7 gets closer to theinner roller 6. As a result, the circumferential surfaces 6 a and 7 a ofthe inner and outer rollers 6 and 7 sandwich the flange 2 b of thetubular body 2 and the circumferential edge 3 a of the end plate 3therebetween. On the other hand, when the swaging section 9 contractsthe cylinder 14 a of the drive mechanism 14, the outer roller 7 is movedwhile being guided by the guide mechanism 13 so that the outer roller 7moves away from the inner roller 6.

As shown in FIG. 5, the robot 5 is, for example, a typical 6-axis robotarm, and its base is connected to a fixing jig 5 a. Meanwhile, the tipof the robot 5 is connected to the swaging section 9. The motor of eachjoint of the robot 5 is controlled based on a control signal suppliedfrom the control unit 10.

The control unit 10 controls the motor of the main body 12 in therotatable table 8, the pressurization/decompression unit 14 b of thedrive mechanism 14 in the swaging section 9, and the motor of each jointof the robot 5. Details of the control will be described later. Notethat the control unit 10 according to this exemplary embodiment controlsthe rotatable table 8 and the robot 5 in cooperation in an interlockingmanner.

Next, a swaging method according to this exemplary embodiment isexplained. Note that the below-explained swaging method may be performedby using hardware resources and/or software resources.

Firstly, an operator disposes the tubular body 2 between the recessedparts 11 h and 11 k of the first and second fixing part 11 a and 11 b ofthe rotatable table 8, and drives the first and second drive mechanisms11 c and 11 d and thereby fixes the tubular body 2 by the recessed parts11 h and 11 k of the first and second fixing part 11 a and 11 b. Then,the operator places the circumferential edge 3 a of the end plate 3 onthe flange 2 b of the tubular body 2 so that the opening 2 a on the topof the tubular body 2 is closed.

Next, as shown in FIG. 2, the control unit 10 disposes the inner roller6 inside the tubular body 2 by controlling the robot 5 and therebybrings the circumferential surface 6 a of the inner roller 6 intocontact with the rising part 3 c of the end plate 3, and disposes theouter roller 7 outside the tubular body 2. In this process, the controlunit 10 makes the pushing mechanism 16 push the planar section 3 b ofthe end plate 3.

Next, the control unit 10 rotates the tubular body 2 and the end plate 3by controlling the motor of the drive mechanism 12 c in the rotatabletable 8.

Next, the control unit 10 extends the cylinder 14 a of the drivemechanism 14 by controlling the pressurization/decompression unit 14 bof the drive mechanism 14 in the swaging section 9 and thereby moves theouter roller 7 toward the inner roller 6, and sandwiches the flange 2 bof the tubular body 2 and the circumferential edge 3 a of the end plate3 by the circumferential surfaces 6 a and 7 a of the inner and outerrollers 6 and 7.

Then, the control unit 10 controls the robot 5 and thereby moves theinner and outer rollers 6 and 7 so that they conform the rotatingtubular body 2 and the end plate 3, i.e., move the inner and outerrollers 6 and 7 along the flange 2 b of the tubular body 2 and thecircumferential edge 3 a of the end plate 3.

Note that FIG. 7 shows a positional relation among the tubular body, andthe inner and outer rollers 6 and 7 when the tubular body 2 is rotated.In particular, FIG. 7 shows a positional relation until the tubular body2 rotates 180°.

As shown in FIG. 7, the control unit 10 controls the rotatable table 8and the robot 5 in cooperation and thereby controls the positions of theinner and outer rollers 6 and 7 so that the straight line L1 is disposedon a normal N1 (of the outer circumferential surface) of the tubularbody 2 that passes through a place (processing point P1) where thetubular body 2 is sandwiched by the circumferential surfaces 6 a and 7 aof the inner and outer rollers 6 and 7 even when the tubular body 2 andthe end plate 3 are rotated.

In other words, the control unit 10 controls the positions of the innerand outer rollers 6 and 7 so that the rotation shafts 6 b and 7 b of theinner and outer rollers 6 and 7 are disposed roughly in parallel with asurface (i.e., a line in the strict sense) where the tubular body 2 issandwiched by the circumferential surfaces 6 a and 7 a of the inner andouter rollers 6 and 7 as viewed in the front/back direction of theswaging section 9, and the direction in which the outer roller 7 movestoward the inner roller 6 is roughly perpendicular to the surface wherethe tubular body 2 is sandwiched by the circumferential surfaces 6 a and7 a as viewed in the vertical direction of the swaging section 9.

As a result, the circumferential surface 6 a of the inner roller 6roughly comes into contact with the surface of the rising part 3 c(i.e., with the line in the rising part 3 c in the strict sense) of theend plate 3, and the circumferential surface 7 a of the outer roller 7roughly comes into contact with the outer circumferential surface (i.e.,with the line in the outer circumferential surface in the strict sense)of the tubular body 2. Further, the extending/contacting direction ofthe cylinder 14 a of the drive mechanism 14 is roughly perpendicular tothe tubular body 2. Therefore, the extending force by the cylinder 14 acan be reliably transferred to the flange 2 b of the tubular body 2 andthe circumferential edge 3 a of the end plate 3.

Note that as shown in FIG. 3, a rotation axis AX4 of the robot 5preferably passes through a processing point P1 and extends in adirection in which the rotation shaft 6 b of the inner roller 6 extends.As a result, it is possible to control the positions of the inner andouter rollers 6 and 7 so that the straight line L1 can be easilydisposed on the normal N1 that passes through the processing point P1even when the tubular body 2 and the end plate 3 are rotated.

Further, when the tubular body 2 is one that is manufactured by swagingopened ends of a roughly U-shaped steel plate, the swaged part ispresent on the outer circumferential surface of the tubular body 2.Therefore, the swaging device 1 preferably has a configuration in whichwhen the outer roller 7 comes to the swaged part, the outer roller 7 canexcellently get over the swaged part.

Therefore, in this exemplary embodiment, the swaging device 1 includes apressure adjustment unit 14 a that adjusts the force for pushing theflange 2 b of the tubular body 2 and the circumferential edge 3 a of theend plate 3 in the outer roller 7 to a value equal to or lower than apredetermined threshold between the cylinder 14 a and thepressurization/decompression unit 14 b as shown in FIG. 2. As a result,it is possible to make the outer roller 7 get over the swaged part ofthe tubular body 2 while pushing the flange 2 b of the tubular body 2and the circumferential edge 3 a of the end plate 3 with an appropriatepressure.

As described above, the flange 2 b of the tubular body 2 and thecircumferential edge 3 a of the end plate 3 are swaged together bysandwiching the flange 2 b of the tubular body 2 and the circumferentialedge 3 a of the end plate 3 by the inner and outer rollers 6 and 7 whilerotating the tubular body 2 and the end plate 3.

As described above, in the above-described swaging device 1 and theswaging method according to this exemplary embodiment, the force forpushing the flange 2 b of the tubular body 2 and the circumferentialedge 3 a of the end plate 3 exerted by the outer roller 7 is roughlyequal to the force acting to push back the outer roller 7 exerted by theinner roller 6, and their reactive forces act on the robot 5 so thatthey cancel out each other. As a result, the reactive force is notsubstantially transferred to the robot 5. Therefore, there is no need toconstruct the robot 5 with a strong structure, thus making it possibleto simplify the robot 5 and to contribute to a reduction in the costthereof.

In addition, since the inner and outer rollers 6 and 7 are moved byusing the robot 5 so that they conform to the rotating tubular body 2and the end plate 3, the conforming mechanism (or copying mechanism) ofconventional swaging devices can be omitted, thus simplifying theswaging device.

Further, since the grasping parts 11 f and 11 i of the first and secondfixing part 11 a and 11 b according to this exemplary embodiment can bereplaced according to the shape of the tubular body 2, the swagingdevice 1 has a high general-purpose property.

Further, in this exemplary embodiment, since the rotatable table 8 andthe robot 5 are controlled in cooperation, the operating range of therobot 5 can be narrowed, thus contributing to a reduction in the size ofthe robot.

Note that FIGS. 8 and 9 show other tubular bodies or the like that canbe swaged by the swaging device 1 according to this exemplaryembodiment. The swaging device 1 according to this exemplary embodimentcontrols the positions of the inner and outer rollers 6 and 7 by usingthe robot 5. Therefore, even when the outer circumferential surface ofthe tubular body 2 is inclined inward or outward (i.e., even when thetubular body 2 is a frustum) as shown in FIG. 8, the flange 2 b of thetubular body 2 and the circumferential edge 3 a of the end plate 3 canbe swaged together by inclining the rotation axis AX4 of the robot 5with respect to the axis that extends in the height direction of thetubular body 2.

Further, even when a part of the opened end of the tubular body 2 isinclined with respect to a surface S1 perpendicular to the axisextending in the height direction of the tubular body 2 as shown in FIG.9, the flange 2 b of the tubular body 2 and the circumferential edge 3 aof the end plate 3 can be still swaged together by inclining therotation axis AX4 of the robot 5 with respect to the axis that extendsin the height direction of the tubular body 2.

Second Exemplary Embodiment

In this exemplary embodiment, a configuration in which the outer roller7 includes a first roller for a coarse process and a second roller for afinishing process as in the case of a typical swaging device isexplained. Note that FIGS. 10 and 11 are plan views showing a swagingsection according to this exemplary embodiment. FIG. 12 schematicallyshows a flow of a swaging process according to this exemplaryembodiment.

As shown in FIGS. 10 and 11, a fundamental configuration of a swagingsection 20 according to this exemplary embodiment is roughly identicalto that of the swaging section 9 according to the first exemplaryembodiment, and therefore duplicated explanations thereof are omitted.However, two swaging sections 9 are arranged roughly in a V-shape asviewed in the direction in which the rotation shaft 6 b of the innerroller 6 extends. Note that the following explanations of the swagingsection 20 are given with reference to the swaging section 20 shown inFIGS. 10 and 11.

A connection section 21 in this exemplary embodiment is formed roughlyin a V-shape as viewed in the vertical direction of the swaging section20. Further, a first guide mechanism 23 and a cylinder 24 of a firstdrive mechanism are provided in the connection section 21 so that afirst roller 22 can be moved toward the inner roller 6. Further, asecond guide mechanism 26 and a cylinder 27 of a second drive mechanismare provided in the connection section 21 so that a second roller 25 canbe moved toward the inner roller 6. Note that the first and secondrollers 22 and 25 are disposed at roughly the same height as each otherin the vertical direction of the swaging section 20.

As a result, as viewed from the vertical direction of the swagingsection 20, a straight line L2 that is perpendicular to the rotationshaft 6 b of the inner roller 6 and connects a rotation axis 22 a of thefirst roller 22 with the rotation shaft 6 b of the inner roller 6 and astraight line L3 that is perpendicular to the rotation shaft 6 b of theinner roller 6 and connects a rotation axis 25 a of the second roller 25with the rotation shaft 6 b of the inner roller 6 are perpendicular toeach other on the rotation shaft 6 b of the inner roller 6.

The above-described swaging section 20 can rotate around the rotationaxis AX4 of the robot 5, and rotates around the rotation axis AX4according to the progress of the swaging process. That is, the first andsecond rollers 22 and 25 revolve around the rotation axis AX4. It shouldbe noted that the rotation axis AX4 of the robot 5 according to thisexemplary embodiment passes through a place (processing point P2) wherethe tubular body 2 is sandwiched by the circumferential surface 6 a ofthe inner roller 6 and the circumferential surface 22 b of the firstroller 22, and extends in a direction in which the rotation shaft 6 b ofthe inner roller 6 extends.

When a coarse process shown in FIGS. 12( a) to 12(c) is performed, thecontrol unit 10 disposes the straight line L2 on the normal N2 (of theouter circumferential surface) of the tubular body 2 that passes throughthe processing point P2 by controlling the position of the swagingsection 20 using the robot 5 and rotating the swaging section 20 aroundthe rotation axis AX4.

Then, the control unit 10 extends the cylinder 24 of the first drivemechanism and thereby moves the first roller 22 toward the inner roller6 while rotating the rotatable table 8. Note that the control unit 10controls the robot 5 and thereby moves the inner roller 6 and the firstroller 22 so that the state where the straight line L2 is disposed onthe normal N2 of the tubular body 2 passing through the processing pointP2 is maintained.

Next, when a finishing process shown in FIGS. 12( d) and 12(e) isperformed, the control unit 10 disposes the straight line L3 on thenormal N3 (of the outer circumferential surface) of the tubular body 2that passes through a place (processing point P3) where the tubular body2 is sandwiched by the circumferential surface 6 a of the inner roller 6and the circumferential surface 25 b of the second roller 25 bycontrolling the position of the swaging section 20 using the robot 5 androtating the swaging section 20 around the rotation axis AX4.

Then, the control unit 10 extends the cylinder 27 of the second drivemechanism and thereby moves the second roller 25 toward the inner roller6 while rotating the rotatable table 8. Note that the control unit 10controls the robot 5 and thereby moves the inner roller 6 and the secondroller 25 so that the state where the straight line L3 is disposed onthe normal N3 of the tubular body 2 passing through the processing pointP3 is maintained.

As described above, this exemplary embodiment makes it possible toselect the first roller 22 for the coarse process and the second roller22 for the finishing process by controlling the robot 5, thus improvingthe productivity. In addition, the common inner roller 6 can be used forboth the coarse process and the finishing process.

The present invention is not limited to the above-described exemplaryembodiments and they can be modified as appropriate without departingthe spirit and scope of the present invention.

Although the above-described exemplary embodiments are explained whiledefining the vertical direction, the left/right direction, and thefront/back direction for clarifying the explanations, they may bechanged as appropriate according to the use of the swaging device.

Although the rotatable table 8 is rotated in the above-describedexemplary embodiments, swaging may be performed by moving the crampingsection along the flange 2 b of the tubular body 2 and thecircumferential edge 3 a of the end plate 3 by using the robot 5 withoutrotating the rotatable table 8.

From the invention thus described, it will be obvious that theembodiments of the invention may be varied in many ways. Such variationsare not to be regarded as a departure from the spirit and scope of theinvention, and all such modifications as would be obvious to one skilledin the art are intended for inclusion within the scope of the followingclaims.

What is claimed is:
 1. A swaging device that swages an end of a tubularbody and a circumferential edge of an end plate for closing an openingof the tubular body by utilizing a processing roller, wherein theprocessing roller is connected to a robot, the robot being configured tocontrol a position of the processing roller, and swaging is performed bysandwiching the end of the tubular body and the circumferential edge ofthe end plate by an inner roller and an outer roller, the inner rollerbeing disposed inside the tubular body, the outer roller being disposedoutside the tubular body so that the outer roller is opposed to theinner roller, and the outer roller being movable toward the innerroller.
 2. The swaging device according to claim 1, wherein the robotcontrols positions of the inner and outer rollers so that rotation axesof the inner and outer rollers are in parallel with a surface sandwichedby the inner and outer rollers in the tubular body, and a direction inwhich the outer roller moves toward the inner roller is perpendicular tothe sandwiched surface.
 3. The swaging device according to claim 1,further comprising a first grasping part and a second grasping part forsandwiching and fixing the tubular body, wherein the first and secondgrasping parts can be replaced according to a shape of the tubular bodyto be fixed.
 4. The swaging device according to claim 1, wherein theouter roller comprises a first roller and a second roller, and astraight line extending in a direction in which the first roller movestoward the inner roller and a straight line extending in a direction inwhich the second roller moves toward the inner roller intersect witheach other.
 5. The swaging device according to claim 1, wherein therobot controls the positions of the inner and outer rollers so thattheir positions conform to the end of the tubular body and thecircumferential edge of the end plate.
 6. The swaging device accordingto claim 1, further comprising a pressure adjustment unit that adjuststhe force for pushing the end of the tubular body and thecircumferential edge of the end plate in the outer roller to a valueequal to or lower than a predetermined threshold.
 7. The swaging deviceaccording to claim 1, further comprising a rotatable table that rotatesthe tubular body, wherein the robot and the rotatable table operate incooperation with each other.
 8. A swaging method for swaging an end of atubular body and a circumferential edge of an end plate for closing anopening of the tubular body by utilizing a processing roller, theswaging method comprising: controlling positions of an inner roller andan outer roller, the inner and outer rollers being the processingroller, the processing roller being connected to a robot; disposing theinner roller inside the tubular body; disposing the outer roller outsidethe tubular body so that the outer roller is opposed to the innerroller; and moving the outer roller toward the inner roller, sandwichingthe end of the tubular body and the circumferential edge of the endplate by the outer and inner rollers, and thereby swaging the end of thetubular body and the circumferential edge of the end plate together. 9.The swaging method according to claim 8, wherein the robot controlspositions of the inner and outer rollers so that rotation axes of theinner and outer rollers are in parallel with a surface sandwiched by theinner and outer rollers in the tubular body, and a direction in whichthe outer roller moves toward the inner roller is perpendicular to thesandwiched surface.
 10. The swaging method according to claim 8, whereinthe robot controls the positions of the inner and outer rollers so thattheir positions conform to the end of the tubular body and thecircumferential edge of the end plate.